Knife sharpener



FIG. 1 is a front elevational view of a knife sharpener, showing my new design, wherein the rear elevational view is a mirror image of the FIG. 1 view;

FIG. 2 is a bottom view of the knife sharpener of FIG. 1;

FIG. 3 is a top view of the knife sharpener of FIG. 1;

FIG. 4 is a side-elevational view of one end of the knife sharpener of FIG. 1 showing a control button; and,

FIG. 5 is a side-elevational view of the knife sharpener of FIG. 1 showing the opposite end to FIG. 4. 

The ornamental design for a knife sharpener, as shown and described. 